Totally agree Derby.
Personally, I think throwing a toddler tantrum and just getting the dog will end very ugly. If he doesn't want a dog, talk to him, ask him why. If he doesn't have valid points have a heart to heart. If he simply does not want another dog, you may just need to accept that rather than putting a strain on your marriage and his trust in you by going and grabbing what you want.
Good luck!
